There is employed a power module with a semiconductor switching device constituting a power conversion circuit such as an inverter and converter (power semiconductor device) stored in one package. Since such a power module has the power semiconductor device arranged in an integrated manner within a package, the effect of down-sizing is great.
For example, Japanese Patent Laying-Open No. 2001-16870 discloses a power module having all semiconductor switching devices of an inverter circuit that converts direct current power into alternating current power in one package. This power module is particularly directed to usage as the power supply of an alternating current motor for driving a vehicle such as hybrid vehicles and electric cars. In accordance with the power module disclosed in this publication, the degree of freedom for the vehicle layout can be increased and the adverse effect caused by the magnetic field generated by the current flow at the wiring can be suppressed by reducing the size of the inverter circuit.
The constraint in layout of various devices in a vehicle has become stricter in order to ensure the comfort of the passenger while obtaining loading space (store ability). Therefore, the power module constituting the power supply for driving the alternating current motor as well as the electric load thereof in the aforementioned hybrid vehicles and electric cars are apt to be restricted in space and arrangement when incorporated in a vehicle.
This induces the problem that, depending upon the position relationship between the output terminal of the power module and the electric load such as the alternating current motor, the arrangement of the wiring and busbar for connection therebetween becomes complicated and/or longer in wiring length. In view of the foregoing, the position of the output terminal of the power module had to be designed individually based on the arrangement and position relationship between the power module and the electric load according to the vehicle layout constraint.
Requirement of such an individual dedicated design will lead to the necessity of modifying the design for each type of vehicle on which the power module, for example, is to be mounted. It will be difficult to reduce the fabrication cost since the components cannot be shared. In other words, for power modules with strict constraint in arrangement layout, it is necessary to increase the degree of freedom from the layout perspective even with respect to the configuration of the output terminal from which power is output in addition to reduction in the size of the device itself. However, the aforementioned publication is silent about such a problem, and provides no disclosure or suggestion of measures thereof.